Digitizer systems are used touch detection in many Human Interface Devices (HID) such as laptops, trackpads, MP3 players, computer monitors, and smart-phones. Some digitizer systems include a capacitive based sensor that senses positioning and proximity of a conductive object such as a conductive stylus or finger used to interact with the HID. Some capacitive sensors typically include a matrix of electrode junctions arranged in rows and columns. The capacitive sensor is often integrated with an electronic display to form a touch-screen.
Signal emitting styluses, e.g. active styluses are known in the art for use with digitizer systems. Active stylus location may be tracked by sampling output from the capacitive based sensor in both row and column direction. Tracking is based on detecting a signal emitted by a tip of the stylus and picked up by the capacitive based sensor due to electrostatic coupling established between the tip and a portion of the matrix of electrode junctions. The position of the stylus is detected and provides input to a computing device associated with the digitizer system.